Gene-environment interaction impacts on heart development and embryo survival.

Congenital heart disease (CHD) is the most common type of birth defect. In recent years, research has focussed on identifying the genetic causes of CHD. However, only a minority of CHD cases can be attributed to single gene mutations. In addition, studies have identified different environmental stressors that promote CHD, but the additive effect of genetic susceptibility and environmental factors is poorly understood. In this context, we have investigated the effects of short-term gestational hypoxia on mouse embryos genetically predisposed to heart defects. Exposure of mouse embryos heterozygous for Tbx1 or Fgfr1/Fgfr2 to hypoxia in utero increased the incidence and severity of heart defects while Nkx2-5+/- embryos died within 2 days of hypoxic exposure. We identified the molecular consequences of the interaction between Nkx2-5 and short-term gestational hypoxia, which suggest that reduced Nkx2-5 expression and a prolonged hypoxia-inducible factor 1α response together precipitate embryo death. Our study provides insight into the causes of embryo loss and variable penetrance of monogenic CHD, and raises the possibility that cases of foetal death and CHD in humans could be caused by similar gene-environment interactions.

ß,γ-Vicinal Dicarbofunctionalization of Alkenyl Carbonyl Compounds via Directed Nucleopalladation.

A palladium(II)-catalyzed 1,2-dicarbofunctionalization reaction of unactivated alkenes has been developed, wherein a cleavable bidentate directing group is used to control the regioselectivity and stabilize the putative alkylpalladium(II) intermediate. Under the optimized reaction conditions, a broad range of nucleophiles and electrophiles were found to participate in this transformation, providing moderate to high yields. 3-Butenoic acid derivatives containing internal alkenes and α-substituents were reactive substrates, offering a powerful platform for preparing ß,γ-substituted carbonyl compounds with multiple stereocenters.

Directed, Regiocontrolled Hydroamination of Unactivated Alkenes via Protodepalladation.

A directed, regiocontrolled hydroamination of unactivated terminal and internal alkenes is reported. The reaction is catalyzed by palladium(II) acetate and is compatible with a variety of nitrogen nucleophiles. A removable bidentate directing group is used to control the regiochemistry, prevent ß-hydride elimination, and stabilize the nucleopalladated intermediate, facilitating a protodepalladation event. This method affords highly functionalized γ-amino acids in good yields with high regioselectivity.

Catalytic, Regioselective Hydrocarbofunctionalization of Unactivated Alkenes with Diverse C-H Nucleophiles.

Reactions that forge carbon-carbon (C-C) bonds are the bedrock of organic synthesis, widely used across the chemical sciences. We report a transformation that enables C-C bonds to be constructed from two classes of commonly available starting materials, alkenes and carbon-hydrogen (C-H) bonds. The reaction employs a palladium(II) catalyst and utilizes a removable directing group to both control the regioselectivity of carbopalladation and enable subsequent protodepalladation. A wide range of alkenes and C-H nucleophiles, including 1,3-dicarbonyls, aryl carbonyls, and electron-rich aromatics, are viable reaction partners, allowing Michael-type reactivity to be expanded beyond α,ß-unsaturated carbonyl compounds to unactivated alkenes. Applications of this transformation in drug diversification and natural product total synthesis are described. Stoichiometric studies support each of the proposed steps in the catalytic cycle.

[Influence of γ-Irradiated Seeds on the Enzyme Activity in Barley Seedlings].

Influence of γ-irradiation of barley seeds (Nur variety) at the doses of 8-50 Gy on catalase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and guaiacol peroxidase activities was studied in the seedlings on the 3, 5 and 7 days after germination. It has been shown that activities of the studied enzymes increase in the dose range that causes the growth stimulation in the seedlings (16-20 Gy).

[Assessment of Cyto- and Genotoxicity of Underground Waters from the Far Eastern Center on Radioactive Waste Treatment Site].

This study has been completed in the frames of activities on the environment assessment in the vicinity of the Far Eastern center (FEC) on radioactive waste treatment (a branch of Fokino, Sysoev Bay). Underground waters collected at the FEC technical site were surveyed both with instrumental techniques and bioassays. Concentrations of some chemicals (ranged to the third hazard category) in the samples collected are over the permitted limits. Activities of 137Cs and 90Sr in waters amount up to 3.8 and 16.2 Bq/l, correspondingly. The integral pollution index is over 1 in all the samples and could amount up to 165. The Allium-test application allows the detection of the sample points where underground waters have an enhanced mutagenic potential. Dependencies between biological effects and pollution levels are analyzed. The findings obtained could be used for the monitoring optimized and decision making on rehabilitation measures to decrease negative influence of the enterprise on the environment.

Method for Sorting and Pairwise Selection of Nanobodies for the Development of Highly Sensitive Sandwich Immunoassays.

Single domain heavychain binders (nanobodies) obtained from camelid antibody libraries hold a great promise for immunoassay development. However, there is no simple method to select the most valuable nanobodies from the crowd of positive clones obtained after the initial screening. In this paper, we describe a novel nanobody-based platform that allows comparison of the reactivity of hundreds of clones with the labeled antigen, and identifies the best nanobody pairs for two-site immunoassay development. The output clones are biotinylated in vivo in 96-well culture blocks and then used to saturate the biotin binding capacity of avidin coated wells. This standardizes the amount of captured antibody allowing their sorting by ranking their reactivity with the labeled antigen. Using human soluble epoxide hydrolase (sEH) as a model antigen, we were able to classify 96 clones in four families and confirm this classification by sequencing. This provided a criterion to select a restricted panel of five capturing antibodies and to test each of them against the rest of the 96 clones. The method constitutes a powerful tool for epitope binning, and in our case allowed development of a sandwich ELISA for sEH with a detection limit of 63 pg/mL and four log dynamic range, which performed with excellent recovery in different tissue extracts. This strategy provides a systematic way to test nanobody pairwise combinations and would have a broad utility for the development of highly sensitive sandwich immunoassays.

[Specific Features of Scots Pine Seeds Formation in the Remote Period after the Chernobyl NPP Accident].

The results of long-term (2007-2011) observations on the quality of seed progeny in Scots pine populations inhabiting the sites within the Bryansk region contaminated as a result of the Chernobyl NPP accident are presented. Formed under the chronic exposure seeds are characterized by a high interannual variability, which is largely determined by weather conditions.

[Modification of Barley Development at Early Stages after Exposure of Seeds to γ-Irradiation].

The reaction of barley seeds (Nur and Grace varieties) to γ-irradiation in the dose range of 2-50 Gy was studied. The length and weight of a root, the length of a seedling and germination rate were investigated. The dose range in which we observed stimulation of plant development was evaluated. It was shown that the increase of root and seedling sizes after irradiation of seeds at stimulating doses is associated with the rise in the developmental speed, rather than with their earlier germination. Also the effects of a dose rate, a quality of seeds, humidity and a period of storage on the manifestation of radiation exposure were studied.

[Polymorphism of Glucose-6-phosphate Dehydrogenase in the Chronically Irradiated Scots Pine Populations].

Polymorphism of glucose-6-phosphate dehydrogenase enzyme was studied in the Scots pine populations growing in the sites of Bryansk region which were radioactively contaminated as a result of the Chernobyl accident. It was revealed that the frequency of mutations in isozyme loci increased along with the level of a dose rate (7-130 mGy/year) in the sites under the study. Significant changes in the activity of this enzyme did not depend on the level of radiation exposure.

Synthesis of α-amino acid derivatives and peptides via enantioselective addition of masked acyl cyanides to imines.

A general, asymmetric synthesis of amino acid derivatives is reported. Masked acyl cyanide (MAC) reagents are shown to be effective umpolung synthons for enantioselective additions to N-Boc-aldimines. The reactions are catalyzed by a modified cinchona alkaloid, which can function as a bifunctional, hydrogen bonding catalyst, and afford adducts in excellent yields (90-98%) and high enantioselectivities (up to 97.5:2.5 er). Unmasking the addition products gives acyl cyanide intermediates that are intercepted by a variety of nucleophiles to afford α-amino acid derivatives. Notably, the methodology provides an alternative method for peptide bond formation.

Diagnostic laparoscopy identifies a peritoneal adenomatoid-like mesothelioma masquerading as ovarian cancer: a case report.

The authors report a rare case of peritoneal adenomatoid mesothelioma in a woman with no history of asbestos exposure. A 61-year-old woman was originally suspected of having a bilateral ovarian tumor based on chest radiography and magnetic resonance imaging (MRI). Upon referral to our hospital, the presence of two solid masses was confirmed by enhanced MRI and 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG-PET/CT). Physical examination was normal, as were serum concentrations of the tumor markers CA 19-9, CA 125, and CEA. Laparoscopic surgery showed a right ovarian tumor and laparoscopic right salpingo-oophorectomy and adhesiotomy were performed. Two months later, the patient underwent laparoscopic segmental resection of the sigmoid colon, with histological analysis identifying an adenomatoid-like tumor. The final diagnosis was peritoneal adenomatoid-like mesothelioma with invasion of the right ovary. This case report demonstrates that imaging techniques must be coupled with laparoscopic surgery for an accurate diagnosis of peritoneal mesothelioma.

[Genotypic identification of the bovine leukemia virus].

Phylogenetic analysis of the sequenced segments of the provirus BLV locus env-gene and the strategy of the PCR-PDRF-genotyping consistent with phylogenetic classification of pathogenic agent and suggested in our works provided taxonomic identification of BLV isolates identified in cattle in Tatarstan (Russian Federation) as representatives of the 4th, 7th, and 8th BLV genotypes. Of 100 identified isolates, 64 represent the 4th BLV genotype, 28 representatives of BLV belong to cluster of the 7th genotype, whereas the other 8 samples of the provirus belong to the new 8th genotype of pathologic agent. The strategy VBL PCR-PDRF-genotyping suggested in our work on the basis of 5 restriction endonucleases (PvuII, SspI, HphI, HaeIII, and BstYI) provided correct genotyping identification of the viral pathogen.

[Antioxidant enzyme activities in Scots pine populations growing under chronic radiation exposure].

The activities of superoxide dismutase, catalase and peroxidase in Scots pine populations growing in the contaminated areas of Bryansk region were investigated. The dose rate at the experimental sites ranged from 7 to 130 mGy/year. It has been identified that the activities ofantioxidant enzymes do not depend on the radiation factor under these dose rates. These doses were found to be insufficient for forming significant physiological effects.

[Evaluation of the partial contribution of naturally occurring radionuclides and nonradioactive chemically toxic elements in formation of biological effects within the Vicia cracca population inhabiting the area contaminated with uranium-radium production wastes in the Komi Republic].

The site contaminated with uranium-radium production wastes in the Komi Republic was studied. The activity concentration of naturally occurring radionuclides (226Ra, 228Th, 238U, 230Th, 232Th, 210Po, and 210Pb), as well as concentrations of nonradioactive chemically toxic elements (Pb, Zn, Cu, As, V, Mo, Sr, Y, and Ba) in the soil samples from the experimental site is 10-183 times higher than reference levels. A chronic exposure to alpha-emitters and nonradioactive chemically toxic elements causes adverse effects in tufted vetch (Vacia cracca L.) both at the cellular (aberration of chromosomes) and population (decrease in the reproductive ability) levels. Radionuclides are the main contributors to the decrease in the reproductive capacity and an increase in the level of the cytogenetic damage in root tip cells of tufted vetch seedlings. As and Pb significantly influence the reproductive capacity of plants. Sr, Zn, Y and P modify the biological effects caused by exposure to radionuclides. Moreover, P and Zn reduce the adverse effects of radionuclides; however, Sr and Y enhance these effects.

[V.I.Vernadskii's theory of the biosphere and modern problems of radioecology].

The importance of Vernadsky's scientific heritage for the present stage of science development was substantiated. His role in the formation of radioecology as an independent scientific discipline was emphasized. The ecological consequences of an anthropogenic increase of the radiation background and the prospects of nuclear energy development were considered.

[Assessment of cyto- and genotoxicity of natural waters in the vicinity of radioactive waste storage facility using Allium-test].

Efficacy of bioassays of "aberrant cells frequency" and "proliferative activity" in root meristem of Allium cepa L. is studied in the present work for a cyto- and genotoxicity assessment of natural waters contaminated with 90Sr and heavy metals in the vicinity of the radioactive waste storage facility in Obninsk, Kaluga region. The Allium-test is shown to be applicable for the diagnostics of environmental media at their combined pollution with chemical and radioactive substances. The analysis of aberration spectrum shows an important role of chemical toxicants in the mutagenic potential of waters collected in the vicinity of the radioactive waste storage facility. Biological effects are not always possible to explain from the knowledge on water contamination levels, which shows limitations of physical-chemical monitoring in providing the adequate risk assessment for human and biota from multicomponent environmental impacts.